The present invention relates generally to a yarn carrier and, in particular, to a yarn winding tube for high speed winding operations. The present invention includes a re-useable tube having yarn identifying markings disposed on a recessed surface.
During the yarn manufacturing process, yarn packages are formed by winding yarn onto yarn carriers that are rotated at high speeds, sometimes in excess of 8,000 rpms. Typically, the yarn carrier is rotated by a drive mechanism that includes a driven roller which contacts the outer surface of the carrier at the start of winding and drives the carrier through frictional engagement between the driven roller and the carrier. As layers of yarn are wound onto the carrier, the driven roller moves radially outward from the carrier, maintaining frictional contact with the outer layer of yarn. A pick-up groove is usually provided at one end of the tube for capturing the yarn and initiating the winding of the yarn onto the tube.
These yarn winding tubes are often made of paperboard or other fibrous materials such as those disclosed in U.S. Pat. Nos. 4,057,201 And 5,328,121.
The life of a laminated paper yarn tube is somewhat limited. Paper tubes are often damaged during shipments and/or winding of the yarn. Disfiguration of the tube may cause uneven rotation during the yarn winding operation. Moisture absorption by the paper tube may also cause changes in dimension and other physical properties. Furthermore, paper tends to create dust, particularly when the driven roller is in contact with the carrier at the start of winding.
Plastic, re-useable winding tubes have been suggested as replacements for paper carriers. Examples of re-useable winding tubes are shown in U.S. Pat. Nos. 4,889,294 and 4,901,941.
One important features of a yarn winding tube is the means for identifying the particular type of yarn on the tube without a detailed inspection of the yarn. A visual symbol or identification mark is often applied to the rim of the tube, above the yarn wound thereon. These markings may be a printed symbol on the ends of the tube. A particularly useful means for yarn identification is to color code the carriers with one or more colored bands on their outer peripheral surfaces. Multiple bands are preferred because they can convey more information than a single colored band. For example, one band may be used to designate the yarn material and another may be used to designate the denier of the yarn. Moreover, providing various combinations of colors allows a greater number of yarns to be identified than if one band were used.
Placing yarn identifying markings on the outer peripheral surface of the carrier, however, exposes them to significant wear from frictional contact with the driven roller during the start of the winding operation, the winding of the first layer of yarn onto the carrier, an handling of carrier while empty. The wearing away of the markings can produce dust that could contaminate the yarn and could collect on the parts of the winding machine, which would require more frequent maintenance and may be more prone to failure. In addition, after prolonged use, the markings may wear away completely, requiring the markings to be reapplied or new carriers to be provided more often than desired.
The present invention is directed to a yarn carrier adapted to be mounted on a winding machine, to have yarn wound thereon and unwound therefrom, and to form a yarn package. The yarn carrier comprises a tube having a first end, a second end and an outer peripheral surface located between the first and second ends. The tube includes a recess formed in the outer peripheral surface that defines a marking surface located radially inward from the outer peripheral surface. The tube further includes at least one marking disposed on the marking surface that is adapted to identify at least one characteristic of the yarn wound onto the carrier.
In another aspect, the yarn carrier of the present invention may include a yarn catching means located in the recess. The yarn catching means may include a roughened portion of the marking surface, slip-resistant coating, a strip having a plurality of hooks or the like.